Some philosophers, particularly the chain-smoking kind, may accept the idea of a predetermined destiny. Either the cancer will come or it won’t. Scientists, however, have recently produced evidence to suggest that getting rid of youthful bad habits in adulthood can have a significant impact in later life. In other words, it’s not too late to improve your health.

A Swedish study published in the British Medical Journal examined the effects of exercise on mortality rates. Middle-aged men who increased their physical activity (and this did not necessarily mean Iron Man events; heavy gardening was enough) could reduce their mortality rate to that of men who had always been highly active. </p><p>The men entered the study at age 50, and were followed at intervals until they were 82. There seemed to be a small increase in mortality for 50-year-olds who upped their physical activity initially, but this disappeared after the age of 60, when they had the same death rate as men who had always been “highly active”. To put this in context, men with low physical activity (sedentary pursuits such as reading and watching television) had a mortality rate of 27.1 per 1,000 person years. Those in the medium category (walking and cycling for pleasure) and the high (recreational sports, hard training or heavy gardening) had mortality rates of 23.6 and 18.4 per 1,000 person years respectively. These decreases may look small, but they compare well beside pharmacological interventions.

And so, to smoking. Half of cigarette smokers die a smoking-related death. The belief that “it’s too late to give up” or “it won’t make any difference at my age” was blown out of the water by a 50-year study performed by the late Sir Richard Doll and his team, and published in 2004 in the BMJ. Again, this was a study of men: almost 35,000 doctors in the UK. Doll studied the effects of smoking on mortality rates and the converse effects of stopping. Men who successfully quit at age 50 halved their risk of dying a smoking-related death. Those who stopped by age 30 avoided almost all of the risk. Even stopping smoking at the age of 60 meant an average gain of about three years in life.

However, I suspect it might be bad form to use this research to justify excessive hedonism (if that’s not a contradiction) in our earlier years. To be on the safe side, perhaps we should stick to more benign pastimes. Personally, I hope that shoe shopping has no discernable impact on mortality.